3. Infection and Response Flashcards
What are pathogens?
Microorganisms that cause disease
What are infectious diseases?
Diseases that can be passed from organism to organism through water, air, direct contact and bites
What are the four types of pathogens?
Bacteria, viruses, protists, fungi
Who was Ignaz Semmelweis?
The man who found out that disease can be spread by not washing your hands ie. direct contact
What type of pathogens are measles?
Viruses
What are the symptoms of measles?
Fever and red skin rash
Treatment / prevention for measles?
People get vaccinated as children
How are measles spread?
Inhalation of droplets from sneezes
What type of pathogen is HIV?
Virus
What type of pathogen is tobacco mosaic virus?
Virus
What type of pathogen is salmonella?
Bacteria
What type of pathogen is gonorrhoea?
Bacteria
What type of pathogen is rose black spot?
Fungi
What type of pathogen is malaria?
Protist
What are the symptoms of HIV?
Flu, and if not treated it can attack the immune system
What are the symptoms of tobacco mosaic virus?
Mosaic pattern, discolouration that affects plant growth
What are the symptoms of salmonella?
Fever, cramps, vomiting, diarrhoea
What are the symptoms of gonorrhoea?
Thick yellow/green discharge from vagina or penis, pain when urinating
What are the symptoms of rose black spot?
Purple/black spots develop on leaves. They turn yellow and fall off
What are the symptoms of malaria?
Recurrent episodes of fever
Treatment / Prevention for HIV?
Antiretroviral drugs
Treatment / Prevention for tobacco mosaic virus?
No treatment
Treatment / Prevention for salmonella?
Poultry vaccinate
Treatment / Prevention for gonorrhoea?
Antibiotic penicillin or barrier method e.g. condom
Treatment / Prevention for rose black spot?
Use fungicides or remove leaves infected
Treatment / Prevention for malaria?
Prevent mosquitos from breeding, use nets to avoid being bitten
How is HIV spread?
sexual contact or exchange of bodily fluids e.g. using the same needles after a blood test
How does tobacco mosaic virus affect plants?
Affects growth due to lack of photosynthesis
How is salmonella spread?
Bacteria spread in food or on food prepared in unhygienic conditions
How is gonorrhoea spread?
Sexual contact
How does rose black spot affect plants?
Affects growth as photosynthesis is reduced
How is rose black spot spread?
By water or wind
How is malaria spread?
Life cycles that includes a mosquito
What are the body’s main barriers to disease?
- tears
- cilia and mucus
- HCl
- skin
How are tears a defence method?
Contain enzymes which make them mildly antiseptic
How is mucus a defence method?
In the respiratory system mucus gathers bacteria which is swallowed
How is HCl in the stomach a defence method?
It contains acid which kill bacteria
How is skin a defence method?
When unbroken it creates a barrier
What does the immune system do?
Tries to destroy any pathogen that gets into the body
Which cells help defend against pathogens?
White blood cells
What are the three types of white blood cell?
- phagocytes - ingest pathogens
- lymphocytes - produce antibodies
- ones that produce antitoxins
What do phagocytes do?
Engulf, ingest then digest pathogens
What do lymphocytes do?
Produce antibodies which destory particular bacteria or viruses
Why do some white blood cells produce antitoxins?
To counteract with toxins released by pathogens
How do bacteria cause disease?
Splitting into 2 and reproducing
Causing damage by releasing toxins
How do viruses cause disease?
Enter body and take over cells, destroy cells as they reproduce
Also cause tissue damage and release toxins
Are bacteria helpful or harmful?
Both - causes salmonella, cholera, typhoid, gonorrhoea
Are viruses helpful or harmful?
Harmful - caused colds, measles, rubella and AIDS
What is immunisation?
Giving protection against many diseases - involved giving a vaccine
What is a vaccine?
A dead or weakened version form of the pathogen
How do vaccines work?
By triggering the immune system by stimulating WBCs to produce antibodies
Pros of vaccination?
- help control infectious diseases
* prevent death or complications from these diseases
Cons of vaccination?
- don’t always work
* some people have bad reactions
How are new strains of a disease formed?
When pathogens mutate (change their DNA) spontaneously
Why are new strains of diseases spread quickly and easily?
No one is immune and there is no effective treatment
What is an epidemic?
A spread of a new strain in one country
What is a pandemic?
A spread of a new strain across more than one countru
What do bacteria need to multiply by cell division?
Enough nutrients and a suitable temperature
How to work out bacteria at the end of a growth period?
bacteria at start x 2 (to the power of number of divisions)
Why do bacteria become resistant to antibiotics?
- if doctors prescribe them inappropriately
* if patients don’t complete their course of medication meaning that not all bacteria is killed
Why can’t antibiotics treat new strains?
Because development is slow
How are monoclonal antibodies made?
Lymphocytes and tumour cells are made into hybridoma cells which can target bacteria and divide
What is a myeloma cell?
A tumour cell
What are the uses of monoclonal antibodies?
- pregnancy tests
- diagnosis
- measuring and monitoring
- research
- treating disease
How do pregnancy tests work?
Monoclonal antibodies bind to hormones made in pregnancy that are passed out in urine and turn test blue
How are monoclonal antibodies used in diagnosis?
They bind to antigens found on pathogens or blood clots which allow doctors to detect problems
How are monoclonal antibodies used in measuring and monitoring?
Hormone levels and chemicals in blood
How are monoclonal antibodies used in treating disease?
They can trigger the immune system to attack cancer cells or can carry toxin drugs for radiotherapy
Advantages of monoclonal antibodies?
- bind only to a specific antigen
- healthy cells not affected
- treat a range of conditions
Disadvantages of monoclonal antibodies?
- more side effects
- expensive to develop
- combining drugs to correct MCAs is difficult
Ways to recognise a diseased plant?
- stunted growth
- malformed stems or leaves
- decay
- discolouration
- growths
What is nitrogen used for in a plant?
Protein synthesis therefore growth
What is phosphorus used for in a plant?
Make roots
What is potassium used for in a plant?
Make flowers / fruits
What is magnesium used for in a plant?
Making chlorophyll
What are the nitrogen deficiency signs?
Stunted growth, yellow leaves
What are the phosphorus deficiency signs?
Poor roots, purple leaves
What are the potassium deficiency signs?
Yellow leaves with dead spots
What are the magnesium deficiency signs?
Leaves turn yellow from bottom
Mechanical defence responses in plants?
- thorns and hairs that deter animals
- leaves that droop when touched so the insect drops off
- mimicry to trick animals so insects won’t lay eggs
Chemical defence responses in plants?
- antibacterial chemicals e.g. mint
* poisons that deter herbivores
Physical defence responses in plants?
- cellulose cell walls
- waxy cuticle on leaves
- layers of dead cells around stems (bark)
- leaf fall
What are non-communicable diseases?
Diseases that are not infectious and cannot be transmitted by microbes
What is ARBD?
Brain damage after long term heavy drinking
What is ARLD?
Liver damage are long term heavy drinking
What are some symptoms of ARLD?
Feeling sick, weight loss, loss of appetite
Why can alcohol cause poverty?
It is expensive to buy and treatments for liver and brain damage are costly
What can smoking do to unborn babies?
Cause premature births and stillborns
What can alcohol do to unborn babies?
Miscarriages, premature births and damage to baby’s brain or spinal cord
Risk factors for cardiovascular disease?
No exercise, smoking and a bad diet
What is chronic obstructive pulmonary disease?
A disease that decreases surface area of alveoli
What are carcinogens?
Substances that cause cancer in living tissue
Sources of ionising radiation?
UV light from sun, X-rays, accidents in nuclear power
